Reducing power consumption is becoming increasingly important and desirable. There is a growing awareness that consumer electronics, including computers, consume power, many times unnecessarily. This has led to a strong trend to reduce electrical usage in consumer electronic devices, including power consumption in computers and monitors. In display devices in particular, such as LCD, LED, and plasma monitors, power consumption can be reduced by addressing the area of video screen refresh. Power is used when a video frame is refreshed, or transmitted, from a source device, such as a computer, to a sink device, such as a monitor. Video refresh is generally needed to prevent fading of an image of a video frame. Video frame refreshing between a source and sink is often done continuously. Video data is constantly sent from the source to the sink. However, when a video frame is static, there is no need for a graphics controller in the source device to constantly transmit video data to a display controller in a sink device over a main link, which, clearly, must be powered on in order to be used for the transmission.
It would be desirable to be able to reduce the number of video frame transmissions over the main link (display interface) from the source device to the sink. This would allow the main link to be turned off for certain time periods. It would also be desirable to be able to turn off the power of the graphics controller when not needed.